This invention shows a cover for box style trailers that may be deployed on a permanent basis or unfurled as a cover for the trailer closed top that has mesh to hold and break into small lumps any snow or ice that collects on the top surface of the trailer.
The problem of debris or other material falling from open trucks loaded with garbage, gravel, dirt or other materials is a long and well documented problem that has resulted in a series of State and Federal requirements for covers on open trucks. The covers both hinder the escape of lumps or pieces of the contents of the open trucks and lowers the emission of particulates removed by the wind of passage. The rules cover such diverse materials as asphalt and corn shipments where covers reduce air polluting dust and vapors to gravel and garbage trucks where material blown out of the truck can hit and damage or hinder vision of other vehicles traveling on roads behind or alongside these open trucks.
There is a problem that is similar in hazards and effects with closed box tractor-trailers. These long flat top trailers in colder times and climates accumulate snow and ice when they are parked in inclement weather. The accumulation that can easily be several inches of ice of up to a foot or more of snow is not easily removed due to the flimsy structure of the trailer box and to the height and lack of access to the trailer box top.
The problem of snow or ice falling from truck tops has caused several serious accidents and there are consistent claims of cars with broken windshields and several reports of injury due to impact of snow and ice falling from the top of trailers.
At present the key art is based upon open truck covers. It consists of safety systems for vehicles and tarpaulin systems where in most cases novel methods of attaching a tarp to the top of an open truck by means of a fixed or traveling unroller and rewinder are employed. The recent U.S. Pat. No. 5,211,440 is typical where moving a handle allows a tarpaulin to be moved from a stored position to its uncovered position, the system being considered in the patent as a safety system.
Another type of truck cover is shown by Dimmer et al in U.S. Pat. No. 4,302,043 where a sidewise tarp is pulled by an unrolling cylinder attached to a universal joint to allow the rotation of the tarp containing cylinder over a series of supports or ropes along the top of an open, full height sided truck thus unfurling the tarp. There are many other systems that cover rolling or unrolling a tarp.
The phrase snow screen does occur in the patent literature as in U.S. Pat. No. 5,564,770 but while the phrase could cause confusion with the concepts herein, snow screens are a windshield covering structure that has interfilding and storing capabilities when the snowscreen is withdrawn. In these usages the word screen is used in the context of covering or blocking material sheltering a surface (windshield) from snow contact. Snow screens in the context of covers for windshields have become popular and exist with magnetic clips, as folded vinyl mats, and as various sun screen configurations.
The problem of snow buildup has been noted in aircraft where a variety of systems to deice or to blow ice from sensitive surfaces by use of flexing membranes, by mechanical disruption or by heat or solvent are known and used in today""s aircraft. In these applications removal of ice totally is required and the form of the removal and the effect of standing snow or ice buildup is not directly addressed since ice covered surfaces just do not work effectively.
Shipboard buildup of ice is also noted but again the rapid removal of ice buildup to prevent top heavy structures is the thrust of the technology and the form of removed material is not a concern with the ocean as a dumping area.
This invention shows the deployment of a mesh containing top cover that is held slightly above the top surface of the trailer. The mesh containing cover has free spacing in the cells of the mesh such that any snow or ice that forms on the top of the trailer engages the mesh surface and is held by the mesh until such time it breaks up into mesh sized lumps and falls from the top of the trailer to the ground or road. The device thus prevents large slabs or lumps of snow or ice from falling from the top of trailers and hitting other vehicles.
Shoveling or even steam removal or automatic brushing of the top of trucks after each snowstorm or ice storm can of course accomplish the problem of minimization of damage from ice and snow on top of trucks. In actual practice the drivers are unlikely to do this since getting up on the ice covered truck is risky and the use of automated equipment is an avoidable cost to the truck owner or operator.
This invention provides a truck topping mesh layer supported a distance of one-eighth inch to six inches from the top of the truck on standoffs or rib-like frames. Since the truck top is an open mesh, the bulk of ice and snow falls through the mesh and is held on top of the truck as the truck starts on a trip. As the truck speeds up, normally the snow and ice would gradually get shaken loose and on a turn, a slowing or an acceleration period, the now loose snow would slip to one side of the truck body in one of more large sheets and fall to the ground. Sometimes there would be a car near that would be hit by the falling sheet of ice or snow. With this invention the mesh prevents the snow or ice layer from sliding to one side of the trailer. As the ice or snow layer becomes loosened from the trailer top, the mesh holds it. As the truck further speeds and wind and evaporation lighten and further loosen the snow or ice layer, the layer breaks up along the mesh cell boundaries and chunks and lumps that are about the size of the mesh break free and fall to the ground rather than large chunks or slabs. The smaller lumps are much less likely to cause harm than the large slabs and chunks. The buildup of ice would also be held in place, ice being more dense and harder to break, the ice would be held as it sublimates by action of the wind and truck speed. Ice would thus be held in place until it melts or breaks into small chunks.
The truck top mesh is held onto the truck in one of several ways. It can be attached to rails along the long axis of the truck, the rails providing further protection against sidewise slab slips. The mesh can also be held by standoffs located along the trailer top edges and throughout the top of the trailer. The standoffs, typically bolted or screwed on metal rods that have top clamps to grip the mesh, are one inch to 6 inches high and provide the required space above the trailer top to make the invention functional.
A considerable advantage to the truck mesh top is that it rapidly breaks up the snow or ice layer, thus rapidly lightening the truck and it further is removable for the 8 to 9 months when snow is unlikely. Being mesh, it has a low wind drag and in fact would fall within the envelope of static air formed by front cowlings on trucks that reduce wind drag effects.